Update Chewing IM MASTER_SITES and HOMEPAGE.
Fix NSS requirement pattern. Fix build.

* firefox-23.0 and seamonkey-2.20 require 3.15 or later of devel/nss.
  The patch is provided by rjs@. Thank you.
Update libchewing to 0.3.5.

What's New in libchewing 0.3.5 (Jul 28, 2013)
---------------------------------------------------------
* Improve CMake rules
  - Visual Studio build included
* Dictionary improvements
  - Remove duplicated phrases, fix Bopomofo representation
  - tool tweaks
* travis-ci support (https://travis-ci.org/chewing/libchewing)
* drone.io support (https://drone.io/github.com/chewing/libchewing)
* coveralls.io support (https://coveralls.io/r/chewing/libchewing)
* editorconfig support (http://editorconfig.org/)
* Add new chewing_set_logger API
* Prevent unaligned memory access
* Reduce maxChiSymbolLen to 39 to avoid overflow
* Do not store user phrase when its length is 1
* Check chiSymbolBufLen in chewing_handle_Numlock()
* Set isSymbol to 0 in SetChoiceInfo
* Fix 'j', 'k' in select mode cannot handle symbol selecting
* Do not call GetCharNext() when GetCharFirst() fails
* Successful stories:
  . FreeArray utilizes libchewing for selecting phrases of Array
    input method


What's New in libchewing 0.3.4 (Dec 31, 2012)
---------------------------------------------------------
* Improve the description of libchewing API
  - Simplified examples to illustrate the usage are added
* Revise libchewing API. Check the documentation for details
* Support THL (Taiwan Huayu Luomapinyin) and MPS2 Pinyin keyboard layout
* Reimplementation of unit test framework. No external 'check' package
  is required
* Fix several phrase errors
  - Add exceptional phrase as well
* Improved developer and user guide
* Introduce CMake based build system, which is convenient to MS-Windows
  based environments.
* Add --enable-gcov to enable gcov coverage
* Fix possible strncat() overflow
* Consistent checks for bopomofo sequence internally
* Handle incomplete bopomofo with space key properly
* Internal structure refactoring
* Read hash path from CHEWING_PATH environment variable
* Make libchewing thread-safe
* Fix IM crash by changing default candidate per page to 10
* Fix the detection of ncursesw
* Fix the usage of autotools
* Update and tune symbols
* Fix valgrind warning
* Fix several compilation warnings
* Fix GCC visibility availability for Darwin specific PIC code
* Fix hash table initialization and its memory leakage
* Support building with mingw32 toolchain
* Fix GNU Hurd build
* Fix Microsoft VC build
* Fix Windows 64-bit build
* Fix mingw32/64 + WINE build
* Successful stories:
 . GCIN supports experimental Chewing IM since version 1.6.4
 . HIME supports Chewing IM
 . UCIMF supports Chewing IM
 . Fcitx supports Chewing IM
 . mozc (IM framework maintained by Google) provides Chewing support
 . JMCCE (reworked version) supports libchewing
Updated inputmethod/libchewing to 0.3.5
Update scim-chewing to 0.3.5.

What's New in SCIM-chewing 0.3.5
---------------------------------------------------------
* Gtk+ 3.x support
* Handle translated Chi-Eng mode switch properly
* Fix incorrect color cand problem
* Support THL (Taiwan Huayu Luomapinyin) and MPS2 Pinyin keyboard
Updated inputmethod/scim-chewing to 0.3.5